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(No Model.) y 2 Sheets-#Sheet l1. I'. G GOULD 8v J..K.fFIRTH. GONGENTRATING MACHINE Patented' Feb. 21, '1893.

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No Model.) 12 sheets-sheet 2. 'E'. G. GOULD & J. K. FIRI'H.

GONGEN'TRATING MACHINE.

No. 492,007. Patented Feb. 21, 1893.

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1w: mams creas no.. Pnoraumn.. wnsumarow D c UNITED STATES PATENT OEEICE.

FRANKLIN G. G OULD, OF BOSTON, MASSACHUSETTS, AND JOSEPH K. FIRTH,` OF SAN FRANCISCO, CALIFORNIA.

CONGENTRATINc-MACHINE.

SPECIFICATION forming part of Letters Patent No. 492,007, dated February 21, 1893.

Application led April 6, 1892. Serial No. 428,057. (No model.) W

T all whom it may concern; end view of Figs. l and 2, with some of the Be it known that we, FRANKLIN G. GOULD, parts removed. Fig. is an enlarged flat of Boston, county of Suffolk, State of Massaview on the bottom of one of thc slats or plates chusetts, and JOSEPH K. FIRTH, of the city comprising the apron or traveling platen on 5 and county of San Francisco, State of Caliwhich is mounted the textile material formfornia, citizens of the United States, have ining the outer or working surface. Fig. 6 is vented certain new and useful Improvements an end view of Fig. 5. Fig. 7 is an edge view in Machines for Concentrating and Saving of Fig. 5,showingthetextile materialmounted Fine Metallic Particles; and we hereby dethereon, also the means of fastening the same 6o 1o clare the following specification and drawto the plates or slats. Fig. 8 is an enlarged ings accompanying the same to be a full, side view of a section of the apron or platen, clear, and exact description of our invention. the propelling bands to which it is attached,

Our invention relates to a method of savand other connected details. ing fine mineral particles, especially of gold Similar letters of reference are employed I 5 and silver, by means of the process commonly in the dierent figures to indicate correspondcalled concentration, bya method in which ing parts. the selection or separation of such fine par- The losses due to the incomplete performticles is attained by indented textile orwoven ance of common concentrating machines is surfaces of fibrous material. well known. The fine particles of metals, or 7o 2o Our invention consists in exposing the their sulphurets, are held in suspension, and

slimes or fine sludge, after treatment by the are not precipitated by the action of water common concentrating processes, to a further and agitation, hence pass off in the slimes and and more perfect residual process, wherein are lost. The peculiar function of surfaces the material is passed over canvas or other composed of textile or woven material for 25 textile surfaces, and in suitable devices for catching and saving such fine metallic particonveying and treating slimes or sludge; also cles is well known, and, to some extent, has in the method of supporting and presenting been applied, but by less perfect means than the textile surfaces so that their operation will is attained by our invention. be continuous and automatic, as set forth Referringnow to the drawings, A A A is a 8o 3o and explained in the drawings hereinafter supporting frame of the usual construction referred to. to which the various parts of the machine are The object of our invention is to save the attached. At the ends of this frame are fine particles of free metal, or sulphurets mounted two shafts, B B2, having on them thereof, that remain in suspension and are wheels or drums C, around which passes the 35 lost when the slimes are treated on iiat surendless apron D, as shown in Figs. l and 2.

faces by agitation and water alone, and when The machine is driven frpm the pulleys E, gravity is depended upon for selection or conplaced at either side of the machine on the centration; also to provide mechanism that shaft B3. To this shaft is geared a short spinwill perform this function without manuel dleF, on the end of which is a worm or tan- 9o 4o labor or attention other than is required in gent screw G meshing into the wheel C3. the ordinary process of concentration, by This wheel C3, drives a second short shaft or means of automatic machinery. spindle F2 on which is a second worm or tan- Referring to the drawings: Figure l is gent screw G2 meshing into the wheel C3, and side elevation of a concentrating machine for from the axis of this wheel a pitch chain Y 9 5 45 ne particles, constructed according to our conveys motion to the shaft B2, giving to the invention. Fig. 2 is a plan view of the same apron D a slow movement toward its highestmachine,having the main portion of the apron end. The method of gearing can be varied or catching surfaces removed. Fig. 3 is an t-o suit the circumstances of any case; the one enlargeddetail,showinga section of thebands shown being the one we employ by preferroo 5o to which the apron is attached, and by means ence.

of which it is propelled. Fig.v 4: is a` partial The material to be treated is fed into a box or hopper H, and is led out through the sluices I, at several points, falling on the apron D, where it meets a supply of water escaping from the tank J, in the usual manner of concentrating machines. From this feeding point the material is carried toward the lowest end of the machineagainst themovementof theapron D by the force of the Water, the sand or gangue falling oif the table at K', While the fine metal particles, which lodge on the face of the platen for reasons hereinafter to be explained, pass on over the other end of the machine at K2. To remove the metallic particles and sulphurets from the apron D, we employ a washing wheel S, driven from the shaft B3 by means of a pulley a, shown in Fig. 2. This Washing wheel S is, in the present case, mounted on a tank L and provided with vanes, so that when inrotation it will dash or discharge the water contained in the tank against the faces of the endless apron D, and thus wash oit the adhering concentrates, which are then carried into the trough or tank N, in front of avertical division e therein, as shown in Fig. l. The main portion of the concentrates, thus washed off, settle in the first division c of the trough or tank N, and are not carried forward by the overflow into the main body of water, and, consequently, do not lodge upon the inner side of the apron D as it passes through the Water in the main part of the trough or tank N. The Wheel S can be mounted at any position with respect to the tank or trough N, and the shaft B2, or, if desired, one or more may be mounted on and operate in a division of the trough or tank N, the purpose being to thoroughly wash the exterior and interstices of the apron D. Thus far the processes we employ are analogous to those known and practiced in concentrating, but the endless apron D, which, with its connections, forms the main part of our invention, operatesv in a different manner, and has special functions in respect to all material that cannot be concentrated or collected by gravity. This apron D is not a continuous web but is formed of a series ofV sections consisting of plates O, preferably made of Wood, covered with canvas and attached to flexible bands C2 that pass around the wheels or drums C at each end of the machine. On their exterior surfaces these slats or bars Oiare covered with sheets of textile material P, preferably a kind of canvas Woven for the purpose and held as shown in Fig. 7, and in the following manner: At the ends of the plates or slats O are fastened angular ledges Q, to which the canvas or covering P is attached. On the .top of this canvas covering are placed transversely other ledges or bars R of triangularsection, which serve to divide the face of the apron into a corresponding number of channels in the direction of its movement and transverse to the main bars or slats O. These ledges Q and R are not fixed centrally on the bars or slats O, but as shown in Fig. 8, projecting over the rear edge to support the edge of the canvas covering P, and

set back from the front edge, so that when the apron is in a straight line, as shown at the top in Fig. l, it will present a continuous surface, and be impervious by means of its sections overlapping, so that no water or material can escape through it.. At the ends, in passing over the drums or wheels C, the slats or bars O assume the position shown in Figs. l and 8, also in passing through the trough or tank N when in a curved form as seen in Fig. l, the joints between the sections being open permits any material lodged there to be washed out.

To attach the bars or slats O to the flexible bands C2 we employ eye bolts 'l, as shown in Fig. 3, and through these eye bolts pass rods U, which, with the coveringpieces V, riveted to the band O2, form a hinge joint, permitting the slats or bars O to assume a tangential position in passing over the wheels ordrums C. Ve do not confine ourselves to these details `of construction which can be varied in various ways to suitiparticular. uses, or for other reasons. The flexible bands G2 can be substituted by a metallic chain, and the slats or bars O attached by various suitable'devices.

To support the apron D at its upper or working surface, We employ shoes or slidesW, `attached at two or more` points on the inner or under face as shown in Figs. 5, G and 7. These shoes or slides move in the supporting guideways X, which have their` bearing on the main frame A,asseen inFigs. l, 2 and et. It will thus be seen that the top or catching surface of the apron D forms a continuous plane of canvas or other suitable textile material, but being reinforced or supported on the bars or slats O, and the projecting ledges R, offers a plane surface uniform throughout. These canvas covered surfaces are shown as flat planes, butitis obvious that the grooves, ripples, or undulations, can be made in these surfaces, the slats or bars Obeing formed with such configuration and the canvas cover fastened thereto. The text-ile covering being relieved ot' all strain, and having in itself no function of support, is not de# stroyed as in vprevious practice when such material has been employed for similarpurposes. The interstices of the Woven fabric, by some peculiar action, supposedly mechanical, catch and retain the tine metallic particlesfof silver, gold, or other metal, permitting the gangue to Wash oif. The apron being-formed of a series of sections the cloth covering can 4be reversed, removed, or renewed, onV any one of the sections, or a part of them, without disturbing the rest, and no injury by accident is liable to occur beyond the covering of` one, or at most a few sectionsat a time.

Having thus described the `nature and objects of our invention, with the manner of constructing and applying'the same, what We claim as new, and desire to secure by Letters Patent, is-

l. In a machine for coucentratingfine metallic particles, an endless apron, moving over IOO IIO

wheels or drums, and guides and composed of hinged textile covered sections, that when in a straight line, or at the top of the machine, will present a continuous surface, impervious to Water or the material treated thereon, substantially in the manner and for the purposes described.

2. In a machine for concentrating line metallic particles, an endless apron, mounted on Wheels or drums, and fixed guides, composed of hinged sections consisting of bars or slats, so joined as to form a continuous plane when the apron is in a straight line, the outer or working surfaces of the sections covered With canvas or other textile material, in the manner and for the purposes substantially as shown and described.

3. In a machine for concentrating tine metallic particles, an endless apron composed of hinged sections as herein described, their outer surfaces covered with canvas or other textile material, and provided With transverse ledges at their ends and intermediate points, so that when the apron is extended in a straight line, these ledges will form parallel channels in the line of the aprons movement, in the manner substantially and for the purposes specified.

4. In a machine for concentrating fine metallic particles, an endless apron consisting of hinged sections, covered on their outer faces with canvas or other suitable textile material, provided with ledges or ribs to form parallel channels when the apron is extended and straight, these ledges or ribs and the textile covering, overlapping at the sides of the bars or slots, so as to form a close joint between them When'the apron is in a straight line on its top or Working side, in the manner substantially and for the purposes herein speciied.

5. In a machine for concentrating tine metallic particles, an endless apron, composed of hinged sections, covered on their outer or working faces with canvas or other textile material, overlapping at their sides, to form an impervious surface when the apron is extended in a straight line, and attached on their inner faces-to a tlexible band or chain by means of hinged joints, so that they Will 

